Since Jonas Salk came up with his polio vaccine, infantile paralysis has virtually disappeared from the United States.

A．surfaced with

B．raised the price of

C．discovered

D．elevated

刘女士，34岁。初孕，孕16周时发现心慌、气短，经查心功能Ⅱ级。经过增加产前检查次数，严密监测孕期经过等，目前孕37周，自然临产

该孕妇在分娩期应注意的问题中，不正确的是

A．常规吸氧

B．胎盘娩出后，腹部放置沙袋

C．采取产钳助产

D．注意补充营养

E．胎儿娩出后常规注射缩宫素